I'm late to the party. Apparently Jewelcrafting isn't as popular as it was before. Blue gems aren't selling for much though the patterns apparently are. I've come to the conclusion that I am leveling a jewelcrafter for nothing.
I've had this issue with several professions so far. Leatherworking, Tailoring, Enchanting, now Jewelcrafting. Engineering remains my favorite but it's not for profit. Not even selling gyro-balanced khorium destroyers is very profitable. Tailoring wasn't really all that profitable but it's great for bags. Enchanting, I don't use it much. If it weren't for the fact that I can sell the supplies for quite a bit of profit I'd drop it as well.
Does anyone out there make a good profit on ANY of the crafting professions?